A genetically informed study of the associations between maternal age at childbearing and adverse perinatal outcomes

We examined associations of maternal age at childbearing (MAC) with gestational age and fetal growth (i.e., birth weight adjusting for gestational age), using two genetically informed designs (cousin and sibling comparisons) and data from two cohorts, a population-based Swedish sample and a nationally representative United States sample. We also conducted sensitivity analyses to test limitations of the designs. The findings were consistent across samples and suggested that, associations observed in the population between younger MAC and shorter gestational age were confounded by shared familial factors; however, associations of advanced MAC with shorter gestational age remained robust after accounting for shared familial factors. In contrast to the gestational age findings, neither early nor advanced MAC was associated with lower fetal growth after accounting for shared familial factors. Given certain assumptions, these findings provide support for a causal association between advanced MAC and shorter gestational age. The results also suggest that there are not causal associations between early MAC and shorter gestational age, between early MAC and lower fetal growth, and between advanced MAC and lower fetal growth.NonePublishe

The Uppsala-Stockholm Assisted Reproductive Techniques (UppStART) study

Purpose: The Uppsala-Stockholm Assisted Reproductive Techniques (UppStART) study is a prospectively recruited sample of couples undergoing assisted reproduction in Stockholm and Uppsala county in Sweden. The study was initiated to (1) investigate possible changes in the epigenetic profile of infants inferred through the ART procedures and their consequence and (2) to assess the impact of lifestyle and health exposures on treatment outcome. Participants: Recruitment took place between September 2011 and December 2013, and in vitro fertilisation (IVF) cycles initiated and pregnancies conceived during this time were followed until December 2014. The cohort includes 971 participants (n= 514 women; n= 457 men), and 129 pregnancies were achieved from the first IVF cycle included in the study. Findings to date: Self-reported demographic, health and lifestyle data were collected from a baseline questionnaire, and to assess changes to lifestyle, a follow-up questionnaire was issued at the time of oocyte retrieval, and at subsequent IVF cycles. Questionnaire data were linked to data extracted from medical records. Biological samples were collected at baseline: blood for extraction of serum, plasma and DNA, morning and evening saliva samples for cortisol measurement and at delivery including samples of maternal blood, placenta and amniotic fluid, and cord blood for epigenetic analysis. Future plans: Through the unique identification number assigned to each Swedish citizen at birth or immigration, UppStART study participants will be linked to the Swedish population-based national and quality registers to provide data from prenatal, obstetrical, neonatal and infant care, and subsequent updates will provide data on childhood health and educational outcomes. Collaboration and use of UppStART data is encouraged, and more information about access can be found at www.ki.se/meb/uppstar